This invention pertains to the valve art, and more particularly to a diaphragm valve of the type used in fluid systems requiring high purity and high reliability.
The assignee of the present invention previously developed a related diaphragm valve as shown and described in detail in U.S. Pat. No. 5,131,627, herein incorporated by reference. That patent discloses a valve assembly that controls flow between inlet and outlet passages that selectively communicate with a valve chamber. A diaphragm is selectively brought into sealing engagement with a valve seat via an actuating stem. The embodiment shown in the drawings of the '627 patent discloses an air actuated valve that reciprocates the stem between open and closed positions.
In selected situations, however, a manually actuated version is desired. The details of this invention are particularly directed to a manually actuated diaphragm valve of this type. It is important to convey to the operator whether the valve is in an open or closed position. Moreover, it may be necessary or advantageous to lock the valve in either its open or closed position, or both positions. It is these features that are particularly addressed in the subject invention.
Other features and advantages of the invention will become apparent from the following detailed description, with reference to the accompanying drawing and claims, which form a part of the specification.